Many Many years ago I read a book about Merlin and King Arthur. My daughter, now a young woman has heard me speak of this book and wants to read it. I can not, for the life of me remember the name or the author.

The story is set in modern times NYC. Arthur is running for Mayor, Merlin had been kept captive in a cave in NYC and has just been set free. Morganna is a crazy old woman who watches the world through her TV and is determined to ruin the election. Can anyone help me figure this one out? I would be so grateful!